Don't start with kalkwasser?

[Randy Holmes-Farley]

You are not adding alk with calcium hydroxide.

Let's work through this carefully.

You are adding calcium, hydroxide, and CO2.

No matter how you precombine them or not, the CO2 has zero effect on the calcium and alkalinity present.

What you do is convert the hydroxide into carbonate and bicarbonate, maintaining the same alkalinity.

OH- + CO2 --> HCO3-

2OH- + CO2 --> CO3-- + H2O

Neither of those steps changes the alkalinity, whether it happens before adding the calcium and hydroxide to the tank, or after.

 

[Randy Holmes-Farley]

You are not adding alk with calcium hydroxide.

Of course you are adding total alkalinity. Hydroxide is one of the components of total alkalinity. In any case, it gets converted into bicarbonate and carbonate instantly on adding to seawater, becoming carbonate alkalinity.

 

[HuduVudu]

if I told you I can see people walking on a planet orbiting alpha centauri using my birding binoculars, would you need to test that out before claiming it isn't true?

Yes. Why wouldn't I? If you insisted maybe you know something I don't. Galaleo insisted that the earth orbits the sun. Heresy!

I have no idea exactly what you are claiming you can do with it.

And this is the problem. This is why I hate debating with you ... you already know. This is just going to devolve AGAIN into another he said she said. You will claim victory in the name of science which you have utterly disregarded. Why can't you just say I don't agree and move on?

Since I maintained my tank perfectly for 20 years using limewater (kalkwasser) alone, it is no surprise that you can do so by using it and also using CO2 (which mitigates the pH rise and allows more concentrated solutions but has not change in the amount of calcium realtive to alkalinity in it.

I am not using limewater I am using calcium hydroxide and I asked you for clarification on which you meant earlier. You didn't answer. If we are talking about limewater then I agree with you and I answered the OP's original question that way.

 

[Randy Holmes-Farley]

Yes. Why wouldn't I? If you insisted maybe you know something I don't. Galaleo insisted that the earth orbits the sun. Heresy!


And this is the problem. This is why I hate debating with you ... you already know. This is just going to devolve AGAIN into another he said she said. You will claim victory in the name of science which you have utterly disregarded. Why can't you just say I don't agree and move on?


I am not using limewater I am using calcium hydroxide and I asked you for clarification on which you meant earlier. You didn't answer. If we are talking about limewater then I agree with you and I answered the OP's original question that way.

Let's keep this civil, and focused on science.

I made it very clear that ANY way of adding calcium hydroxide and CO2 will ALWAYS result in 20 ppm calcium for each 2.8 dKH of total alkalinity. CO2 cannot ever alter the alkalinity of seawater or any water solution. It is a fundamental princliple of water chemistry that even has a name: "The principle of Conservation of alkalinity"

I think it is clear why from above posts of mine, but I am happy to explain further.

 

[Randy Holmes-Farley]

I discuss that principle here:

Chemistry and the Aquarium: What is Alkalinity?

Randy provides an overview of alkalinity as to why it's important, how it's measured, and how can it be tested.

reefs.com

Alkalinity Facts
There are several facts about total alkalinity that follow directly from the definition. Unfortunately, some of these have been misunderstood by some hobby authors.

One of these facts is termed The Principle of Conservation of Alkalinity by Pankow (“Aquatic Chemistry Concepts”, 1991). He shows mathematically that the total alkalinity of a sample CANNOT be changed by adding or subtracting CO2. Unfortunately, there is an article available on line, which claims otherwise, and encourages people to “lower alkalinity” by adding CO2 in the form of seltzer water. This is simply incorrect.

Forgetting the math for the moment, it is easy to see how this must be the case. If carbonic acid is added to any aqueous sample with a measurable alkalinity, what can happen?

Well, the carbonic acid can release protons by reversing equations 1 and 2:

(5) H2CO3 ==> H+ + HCO3–

(6) HCO3– ==> H+ + CO3—

These protons can go on to reduce alkalinity by combining with something that is in the sample that provides alkalinity (carbonate, bicarbonate, borate, phosphate, etc). However, for every proton that leaves the carbonic acid and reduces alkalinity, a new bicarbonate or carbonate ion is formed that adds to alkalinity, and the net change in total alkalinity is exactly zero. The pH will change, and the speciation of the things contributing to alkalinity will change, but not the total alkalinity.

This is not true for strong acids, however. If you add hydrochloric, sulfuric or phosphoric acids (or any acid with a pKa lower than the carbonic acid endpoint), there will be a reduction in the alkalinity.

 

[Randy Holmes-Farley]

And this is the problem. This is why I hate debating with you ... you already know. This is just going to devolve AGAIN into another he said she said. You will claim victory in the name of science which you have utterly disregarded. Why can't you just say I don't agree and move on?

Because you are unquestionably wrong. I am making sure that readers of this forum are not misled.

This is not an opinion issue. it is a fact issue that you have wrong.

 

[HuduVudu]

Let's keep this civil, and focused on science.

I made it very clear that ANY way of adding calcium hydroxide and CO2 will ALWAYS result in 20 ppm calcium for each 2.8 dKH of total alkalinity. CO@ cannot ever alter the alkalinity of seawater or any water solution. It is a fundamental princliple of water chemistry that even ahs a name: "The principle of Conservation of alkalinity"

I think it is clear why from above posts of mine, but I am happy to explain further.

You are assuming fresh water. What are your calculations in salt water? What are the parameters on your salt water solution including CO2?

EDIT: I have a recipe that proves this incorrect. It is reproducable.

 

[Randy Holmes-Farley]

You are assuming fresh water. What are your calculations in salt water? What are the parameters on your salt water solution including CO2?

I made no assumption of the nature of the water involved, nor does Pankow in his calculations. As long as what you added remains in solution rather than precipitating out, the effect is the same.

If something precipitates out, and you are not dosing those solids, then you may get something odd.

For example, if you add calcium hydroxide to magnesium chloride solution, you will precipitate magnesium hydroxide and effectively be dosing calcium chloride.

 

[HuduVudu]

I made no assumption of the nature of the water involved, nor does Pankow in his calculations. As long as what you added remains in solution rather than precipitating out, the effect is the same.

If something precipitates out, and you are not dosing those solids, then you may get something odd.

For example, of you add calcium hydroxide to magnesium chloride solution, you will precipitate magnesium hydroxide and effectively be dosing calcium chloride.

As stated in the edit .. I have a recipe and it is reproducable.

 

[Trever]

At least, I have a better appreciation for the potential problem with starting the kalkwasser, so thanks all. Going to review those equations @Randy Holmes-Farley, it's been a long time, but my college major was chemistry.

Now if only the information here could magically run my red sea calcium test for me, I've still been too lazy to wrestle with that titration looking thing! The Hanna alk checker is nice, it's obvious why that is so popular and was recommended.

Meantime no rush... my corals are doing well. I'd like to push some numbers up because I believe things will grow faster, at the very least, and the various other benefits.

I'm not sure if it's wise to start any dosing though when all I have are 8 nubbins (stony corals). On the other hand, the birdsnest I got last night is a bit of a colony (a very small bush- a "bushlet"), and then there's the remarks about correcting early because bacterial growth.

 

[Randy Holmes-Farley]

As stated in the edit .. I have a recipe and it is reproducable.

To do what?

To add a lot of calcium and alk in a ratio of 2.8 dKH to 20 ppm calcium? I definitely believe that. Any other claim for a clear solution without precipitate is incorrect.

You precipitated magnesium hydroxide when you added calcium hydroxide and CO2 to seawater, and hence got a messed up solution in your recipe. If you think that is useful, go for it. I don't. It's a weird mix of high calcium, low magnesium, and some alkalinity.

 

[HuduVudu]

To do what?

To add a lot of calcium and alk in a ratio of 2.8 dKH to 20 ppm calcium? I definitely believe that. Any other claim for a clear solution is incorrect.

320ppm calcium and 25dKh
Multiply 320 by .0625 to get 20 then mulitply 25 by .0625 to get 1.5625.

Believe what you want Randy, these are the numbers and I can reproduce these results.

Forgot I got 500 for the calcium so the correction is .04 that makes the dKh based on that ... 1.

 

[Randy Holmes-Farley]

320ppm calcium and 25dKh
Multiply 320 by .0625 to get 20 then mulitply 25 by .0625 to get 1.5625.

Believe what you want Randy, these are the numbers and I can reproduce these results.

In the post above yours I explained how you precipitated magnesium hydroxide to lower the magnesium and alkalinity and boosted the calcium of that seawater.

If that sounds like something you want to dose, by all means do so.

Personally, i cannot imagine why one would do that. It will cause issues that you will have to correct by independent alk and magnesium additions.

 

[HuduVudu]

In the post above your I explained how you precipitated magnesium hydroxide to lower the magnesium and alkalinity and boosted the calcium of that seawater.

I use Kalk+ from Brightwell. It has MgOH.

EDIT: I will check the Mag. See I really will check to see if you told me I can see people walking on a planet orbiting alpha centauri using my birding binoculars.

 

[Randy Holmes-Farley]

At least, I have a better appreciation for the potential problem with starting the kalkwasser, so thanks all. Going to review those equations @Randy Holmes-Farley, it's been a long time, but my college major was chemistry.

Hey, welcome fellow chemist!

Glad we could help.

 

[SMSREEF]

I use Kalk+ from Brightwell. It has MgOH.

I am using calcium hydroxide

Your posts are very confusing.
What exactly is your recipe?
How much exactly do you dose?
And how much does it raise your Alk and how much does it raise your calcium?
And what test kits do you use?

 

[HuduVudu]

Your posts are very confusing.
What exactly is your recipe?
How much exactly do you dose?
And how much does it raise your Alk and how much does it raise your calcium?
And what test kits do you use?

Read the post linked in my signature.

 

[Randy Holmes-Farley]

I use Kalk+ from Brightwell. It has MgOH.

EDIT: I will check the Mag. See I really will check to see if you told me I can see people walking on a planet orbiting alpha centauri using my birding binoculars.

It has almost none (read the exact recipe). It is a highly misleading claim of theirs. It also will not dissolve into normal limewater (without your special recipe of CO2 and/or salt water). Thus it is of very little use to real users.

Brightwell Aquatics - Kalk+2

Calcium (min) 54.20% (542,000 ppm), Strontium (min) 1.00% (10,000 ppm), Magnesium (min) 0.15% (1,500 ppm)

That is a Mg/Ca ratio of 0.0028. That is less than corals use

Laughably, that is actually LESS than the impurity magnesium in the commercial calcium oxide (quicklime) material that I tested and many of us used (from Mississippi Lime Co.). It has a Mg/Ca ratio of 0.0038.

 

[SMSREEF]

Read the post linked in my signature.

You have no signature

 

[HuduVudu]

It has almost none (read the exact recipe). It is a highly misleading claim of theirs. It also will not dissolve into normal limewater (without your special recipe of CO2 and/or salt water). Thus it is of very little use to real users.

Brightwell Aquatics - Kalk+2

Calcium (min) 54.20% (542,000 ppm), Strontium (min) 1.00% (10,000 ppm), Magnesium (min) 0.15% (1,500 ppm)

That is a Mg/Ca ratio of 0.0028. That is less than corals use

Laughably, that is actually LESS than the impurity magnesium in the commercial calcium oxide (quicklime) material that I tested and many of us used (from Mississippi Lime Co.). It has a Mg/Ca ratio of 0.0038.

So it is really just expensive Calciume Hydroxide? That's good to know.